Added a new message status to MmsDatabase to signify a pending MMS downl...

...oad which requires APN settings. Added a database method to query MMS messages based on status. Added login to SendReceiveService for processing of MMS pending APN information. Moved all APN/MMS settings into ApnPreferencesActivity and transformed PromptApnActivity into a simple informational activity. Added logic to check for APN settings on send and receive of all MMS (media, group, email) and direct user to PromptApnActivity then ApnPreferencesActivity if necessary. Vocab/grammar adjustments.